Study Material — 1 PYQs (2019–2019) · Concept Notes · Shortcuts
RRB Group D Successive Profit & Loss is a frequently tested subtopic — 1 previous year questions from 2019–2019 papers are included below with concept notes, key rules and shortcut tricks.
RRB Group D Successive Profit & Loss — Past Exam Questions
1 questions from actual RRB Group D papers · all shown free · click option to reveal solution
Exam Q 12019Previous Year Pattern
A shopkeeper buys an article and sells it at a profit of 20%. If he had bought it at 10% less and sold it for ₹6 more, he would have gained 40%. What is the original cost price of the article?
Concept Notes
Successive Profit & Loss— Rules & Concept
Core ConceptRead this first — the foundation of the topic
Core Concept
When profits and losses are applied one after another, we cannot simply add or subtract the percentages. Each percentage change acts on the new value, not the original price
Key Rules
If successive changes of a% and b% occur, the net effect formula is: Net% = a + b + (ab)/100. Use positive values for profit and negative values for loss. For three successive changes a%, b%, c%, first find net effect of any two, then apply the third change.
Formula BlockMemorise — at least one formula appears in every paper
• Overall profit/loss = Net% of original cost price
Exam PatternsWhat examiners ask — read before attempting PYQs
Questions typically involve 2-3 successive transactions. Common scenarios include buying-selling chains, discount followed by profit, or multiple markups. SSC often asks for overall profit/loss percentage or final selling price.
ShortcutsUse these to save 30–60 seconds per question
For quick calculation, convert percentages to multipliers. 20% profit = 1.2, 10% loss = 0.9. Multiply all factors: 1.2 × 0.9 = 1.08 = 8% overall profit.
Worked ExampleSolve this step-by-step before moving on
1
Step 1
Identify the changes
First transaction: +20% (profit)
Second transaction: -10% (loss)
2
Step 2
Apply the formula
Net% = a + b + (ab)/100
Net% = 20 + (-10) + (20 × (-10))/100
Net% = 20 - 10 - 200/100
Net% = 10 - 2 = 8%
3
Step 3
Verify using multiplier method
Final value = 1000 × 1.20 × 0.90 = 1000 × 1.08 = 1080
Profit = 1080 - 1000 = 80
Profit% = 80/1000 × 100 = 8%
Answer: 8% overall profit
Alternate Method using SP calculation:
After first sale: 1000 × 120/100 = 1200
After second sale: 1200 × 90/100 = 1080
Net profit = 1080 - 1000 = 80
Profit% = 8%
Exam TrapsCommon mistakes students make — avoid these
Students often add percentages directly (20% - 10% = 10%) ignoring the compounding effect. Always remember that each subsequent percentage works on the changed value, not the original price. The interaction term (ab)/100 is crucial and frequently overlooked.
Key Points to Remember
Successive changes cannot be added directly due to compounding effect
Formula for two changes: Net% = a + b + (ab)/100
Use positive values for profit, negative for loss in the formula
Multiplier method: Convert percentages to decimals and multiply
Each subsequent change acts on the new value, not original price
Interaction term (ab)/100 is often the key to correct answers
Three changes: Find net of first two, then apply third change
Final amount = Original × (100+a)/100 × (100+b)/100
Exam-Specific Tips
Net percentage formula for successive changes: a + b + (ab)/100
20% profit converts to multiplier 1.2, 25% loss converts to 0.75
For equal successive profits of x%, net effect is x + x + x²/100
Two successive discounts of 10% each give net discount of 19%
Successive changes of +50% and -20% result in +20% net change
Three successive profits of 10% each give net profit of 33.1%
Formula remains same whether dealing with CP, SP, or marked price
Practice MCQs
Successive Profit & Loss — Practice Questions
3graded MCQs · easy to hard · full solution & trap analysis
A shopkeeper buys an item at ₹500. He marks it up by 20% and then offers a discount of 10% on the marked price. Later, he sells the remaining stock at a further discount of 5% on the already discounted price. What is his overall profit percentage on the item?
Practice 2medium
A shopkeeper buys an item at ₹500. He marks it up by 40% and then offers a discount of 10% on the marked price. Later, he sells the remaining stock at a further discount of 20% on the already discounted price. What is his overall profit percentage on the items sold in the second batch?
Practice 3hard
A shopkeeper buys goods at a certain price. He marks up the price by 40% and then offers two successive discounts of 10% and 15% on the marked price. Later, he realizes he made an error in his cost calculation and actually paid 20% less than he initially thought. If his final profit percentage (based on the actual cost) is 1.92%, find the marked price as a percentage of the actual cost price.
60-Second Revision — Successive Profit & Loss
Remember: Net% = a + b + (ab)/100 for two successive changes
Trick: Use multipliers for faster calculation - multiply all factors
Formula: SP = CP × (100+a)/100 × (100+b)/100
Trap: Never add successive percentages directly
Method: For three changes, find net of any two first, then apply third
Quick check: Positive result means profit, negative means loss